Is it safe to mix phentermine and triamterene?

Yes: There is no known potential interaction. However, i personally don't recommend use of Phentermine as it has too many side effects to offset it's only temporary use for weight reduction.

Phentermine Unsafe: Phentermine, is unsafe on it's own. It is dangerous to your heart and your health. And on top of that it is not going to lead to any real or sustained weight loss. I would strongly and kindly advise you to throw it away and not to use it.

Drug interaction: Phenyeramine is used for weight control but can cause tachycardia triamterene is a diuretic and can cause blume depletion make sure your regimen is supervised.